Method of shear cutting envelope blanks



United States Patent Milton A. Stovall Altoona, Pennsylvania [2]] Appl. No. 828,040

[22] Filed March 10, 1969 [45] Patented Sept. 8, i970 {73] Assignee F.L. Smithe Machine Company, Inc.

Duneansville, Pennsylvania a corporation of New York Division of Ser. No. 667,212, filed Sept. 12, i967, now Pat. No. 3,465,626.

[72] Inventor [54] METHOD OF SHEAR CUTTING ENVELOPE BLANKS 2 Claims, 10 Drawing Figs.

[52] U.S.Cl 83/23,

83/55, 83/341, 83/436. 83/91 l [Si] lnt.Cl B26fl/38 [50] Fleldolseareh 83/2150.

[56] References Cited UNITED STATES PATENTS 3,l06,l2l l0/l963 Novick Primary Examiner-James M. Meister Attorney-Nelle and Nolte ABSTRACT: A method of shear cutting envelope blanks having a plurality of pairs of rollers for advancing envelope blanks, for example, at least one of the rollers of the first pair of rollers is tilted in a vertical plane with respect to the direction of blank travel. The cutting knife is perpendicular to blank travel but the blank is diverted angularly by the first vertically tilted roller while moving generally longitudinally to provide progressive or shear cutting. A second pair of rollers,

with at least one of the rollers of this pair tilted in a vertical plane, relocates the blank along its original path.

Patented Sept. 8, 1970 3,527,127

var/01v TYPE I 01. 0mg MEANS I I ATTORNEYS Patented Sept. 8, 1970 3,527,121

INVENTOR MLTd/V 4- Emma.

ATTORNEYS METHOD OF SHEAR CUTTING ENVELOPE BLANKS This application is a division of application Ser. No. 667,212, filed Sept. 12, I967, now Patent No. 3,465,626.

This invention relates generally to a method of shear cutting envelope blanks including rotary panel cutters, for example the type used in evelope making machines to cut the windows in the envelope blanks and more particularly to the angular relationship of the several pairs of rollers or cylinders at the window cutting station with respect to input and output cylinders thereof.

Rotary panel cutters are used in envelope making machines in order to cut windows in the envelope blanks. In the past it has been found desirable to provide a progressive cutting action by angling the knife approximately one and a half degrees with respect to the longitudinal axis of its supporting shaft. In this manner the long edge of the knife that is cross wise of the envelope blank starts to cut beginning at one end and the cut progresses across the blank as the knife and anvil cylinders rotate together.

It is necessary that the window panel be cut parallel with the top and bottom score lines of the envelope blank. Accordingly, in the past it was necessary to feed the blank at the same angle at which the knife is set on its shaft. This required that the feed mechanism and all its cylinders, the printers, the patchers and other mechanisms operating on the blank between the feeder and the patcher must be oriented to bandle and operate on a blank that is set at an angle. It was also necessary that the vacuum holes in the transfer cylinders in the feed cylinders, in the impression cylinders and other feeding and handling devices be set initially during manufacture at the required angle. Further, all adjustable features such as corner posts, guides and other movable members had to be very carefully adjusted to the exact same angle in order to provide good registration of printing, panel cutting, patching, etc. In the prior art construction it was required that the flexographic printing plates be very carefully made up and set on the type cylinders to exactly match the feed angles. In the prior art devices it was necessary to take particular care with the gummers for patching. These members also had to be made up at the particular angle at which the knife was set.

The method of the present invention provides several very important advantages over prior art devices. An important feature of this invention is that all operations on the envelope blank, both before and after the panel cutting is done, is performed with the blank oriented parallel to its direction of movement. That is, the blank itself is not skewed with respect to its line of movement. Thus the complex machining and as sem bling of the prior art structure is avoided.

In one embodiment of the present invention the transfer of the blank from cylinder to cylinder is made between the cylinders and over a very small gap. The angle of tilt of the knife cylinder, and of course the anvil cooperating therewith, is exactly the same as the output cylinder. The knife is angularly set on the cylinder at the same angle at which the cylinder is tilted.

During transit between the cutting cylinder and its anvil the blank travels along a path that is at a predetermined angle in order to permit progressive cutting. The blank is not skewed and is returned to the transfer cylinder along an angular path to assume its original position, so that other operations may be performed thereon. The blank both before and after the panel cutting operation is straight and true with the machine frames on exactly the centerline of the machine.

While the present invention will be described and illustrated primarily with reference to a tilted knife cylinder and anvil, it should be clearly understood that the scope of the invention is not limited to such construction. For example, proper blank orientation and reorientation will be achieved if the knife cylinder and anvil are not tilted but if one ofa pair of cylinders before and one of a pair cylinders after the knife cylinder are tilted in the manner described.

Still another alternative embodiment of this invention contemplates having one pair of cylinders, nominally called the input cylinders, one of which is tilted in a vertical plane and a second pair of cylinders referred to as the output cylinders and operating subsequent to the window cutting operation, one of which is tilted in a vertical plane at an opposite angle to the input cylinders. Whereas the first embodiment requires the blank to travel over one tilted roller and under the other tilted roller, this last embodiment provides that the blank travels in the same direction either over or under both tilted rollers.

Accordingly, it is an object of this invention to provide an improved method for shear cutting envelope blank.

Another object of this invention is to provide an improved method incorporating rotary cutting means for forming a window in an envelope.

A particular object of this invention is a method for cutting envelope blanks in an envelope making machine wherein the cutting cylinder and the anvil associated therewith are tilted in a vertical plane.

A particular object of this invention is a method of cutting envelope blanks including rotary cutting means for forming the window and envelope blank wherein the blank is always oriented parallel to the direction of movement and is operated on in that position.

Another object of this invention is to provide, in combination with the aforementioned method, an output cylinder downstream of and parallel to the tilted knife cylinder, the output cylinder being tilted to the same degree as the knife cylinder and wherein the cutting knife is angled with respect to the longitudinal axis of the knife cylinder.

Yet another object of this invention is to provide suction type movement of the envelope blank from one cylinder to the next and in addition to provide rectilinear movement of the blank across at least the cutting or knife cylinder.

These and other features, objects and advantages of the invention will, in part, be pointed out with particularity and will, in part, become obvious in the following more detailed description of the invention, taken in conjunction with the accompanying drawing, which forms integral part thereof.

In the various figures of the drawing like reference charao ters designate like parts.

In The Drawing:

FIG. 1 is a schematic plan view showing four adjacent cylinders in the window cutting section of an envelope making machine;

FIG. 2 is a schematic end elevational view of the four cylinders shown in FIG. 1;

FIG. 3 is a transverse sectional view taken along lines 3-3 of FIG. 1;

FIG. 4 is an elevational view taken between adjacent cylinders along lines 4-4 of FIG. 1;

FIG. 5 is a schematic developed view illustrating the transfer of an envelope blank between the input cylinder and the knife cylinder shown in FIG. 1;

FIG. 6 is a schematic side elevational view of still another alternative embodiment of this invention;

FIG. 7 is a schematic side elevational view of still another alternative embodiment of this invention;

FIG. 8 is a schematic side elevational view of a further embodiment of the invention; and

FIGS. 9 and 10 are schematic side elevational views of still other alternative embodiments of this invention, wherein the input tilted cylinder is in a different plane from the output tilted cylinder.

Referring now to FIG. 1, there is schematically shown the window cutting section I0 of an envelope making machine and including several parallel cylinders rotatably mounted in the machine frame. The envelope blanks E are delivered to the knife cutting section I0 by conventional means, not shown. Each envelope blank is comprised ofa body portion B in which the window W is cut, side flaps SF and end flaps EF. Conventional suction means may be used to hold the blank on the cylinder whenever required. After the envelope blank traverses the window cutting section it is delivered to conventional envelope folding apparatus not shown.

A feature of this invention is that the envelope blank is delivered to the knife cutting section and is removed from the knife cutting section in a position that is parallel to its line of direction and to the side frames of the machine. In addition, while in the knife cutting section the envelope blank is oriented in a manner such that its angle relative to the knife axis of the cylinder just equals the angle of the knife on the knife cylinder, thus providing means for cutting the window opening parallel to the score lines S of the envelope blank. In other words, the envelope blank is not angularly reoriented while within the window cutting section as was the case in much of the prior art that provided progressive knife cutting action. Instead, the progressive or shear cutting of the window opening is provided while the blank remains parallel to the machine at all times and while the blank travels along an angled path during the window cutting operation. The parallel oriented blank moves along the angled path downstream of the cutting knife.

In the first embodiment of this invention the knife cutting section is comprised of four adjacent cylinders that are parallel to each other and rotatably supported within the machine frame. The four cylinders involved are an input cylinder 12, a knife cylinder I4, having a panel cutting knife 16 secured to the surface thereof, an output cylinder 18 and a transfer cylinder 20. An anvil member in the form of a cylinder, not shown, is positioned parallel, in cooperating relationship to the knife cylinder and is spaced therefrom by a dimension sufficient to accommodate the thickness of the envelope blank. While not illustrated in great detail since it is conventional in the art, the system includes ports and ducts that provide suction and air pressure to the cylinders so that the envelope blank when passing therearound may be secured and held to the surface and so that the window that is cut out of the blank, may be ejected therefrom. In the embodiment shown in FIG. 2 and FIG. 3, the path of a blank is around the underside of the input cylinder, over the topside of the knife cylinder, around the underside of the output cylinder and then over the top surface of the transfer cylinder from which point it is delivered to a conventional folding mechanism. The means for timing the application of suction and air pressure to the blanks as it traverses the various cylinders is well known in the art and need not be described in detail.

FIGS. l-4 illustrate an important feature ofthis invention. It is to be noted that the envelope blanks at the entry to the window cutting station are disposed square with their line of travel. While in the window cutting section and when removed from the window cutting section the blank remains in this squared off position. By way of contrast to the prior art structure, such as is exemplified by U.S. Pat. No. 3,106,!2l issued to A. Novick on October 8, I963, progressive knife cutting action is used to form the window opening even though the blank is not reoriented with respect to its line of travel. This is accomplished by first tilting the knife cylinder 14, the anvil associated therewith and the output cylinder I8 in a vertical plane only through an angle a and, in addition, by orienting knife 16 at an angle a with respect to the longitudinal axis of the knife cylinder. It should be noted that the angle a of the knife with respect to its cylinder is the same as the vertical inclination of the knife cylinder and anvil with respect to a theoretical horizontal plane.

As shown particularly in FIG. 5, as the envelope blank is transferred from the input cylinder to the knife cylinder it remains parallel to its line of travel but it is displaced laterally along an angular path. Because of the angular relationship of the knife with respect to the knife cylinder, the cutting action taking place on the blank will, therefore, be progressive. Thus the first transfer between the input cylinder and the knife cylinder imposes the desired lateral displacement on the blank for cutting the window panel whereas the tilt of the output cylinder subsequent to the knife cylinder exactly compensates for this displacement and repositions the blank along the center line of the machine parallel with the machine frame.

It should be noted that the output cylinder may or may not be immediately adjacent to the knife cylinder. In certain instances it may be desirable to position cylinders 14 and 18 as shown while in other instances cylinder I8 may be further downstream of cylinder 14. The extent of the blank displacement during transit through the panel cutter is exactly pre dictable and the blank always returns to the transfer cylinder for other operations in a position that is straight and true with the machine frames and exactly on the center line of the machine.

Still another embodiment of this invention is shown schematically in FIG. 6. Therein a combination of wrapping transfer of the blank and rectilinear transfer of the blank is employed. The tilting of the knife cylinder and the output cylinder only in a vertical plane and the orientation of the cutting knife at the same angle as the tilt of the knife cylinder remains the same as in the previous embodiment.

In the embodiment shown in FIG. 6 there are a plurality of parallel cylinders 30, 32, 34, 36, 38 and 40. Pressure rollers 42, 44 and 46 cooperate with cylinders 32, 34 and 36 respectively. The envelope blank is fed in from the left and progresses towards the right as seen in FIG. 6. The envelope blank passes underneath cylinder 30 and is transferred to the top surface of cylinder 32 at. a point that is tangent to both the aforementioned cylinders. The blank then passes between cylinder 32 and roller 42, proceeds between cylinder 34 and roller 44 and then is passed in between cylinder 36 and roller 46. The blank is transferred then to cylinder 38, passes below that cylinder whereupon it is transferred to cylinder 40 and traverses the top surface thereof before being delivered to the flap folding portion of the envelope making machine. The advantage derived from the construction shown for the first em bodiment is also provided for the second embodiment. While the suction and air pressure means for the window patch are not shown, it is to be understood that structure conventional in the art is employed.

FIG. 7 illustrates an alternative embodiment of this invention. Rollers 50, 52, S4, 56, 58 and 60 are suitably journalled in the side frames of the machine. The cutter knife such as the type described in connection with the first embodiment is secured to roller 54 at an angle to the axis thereof whereby it is positioned in cooperating relationship with anvil 62. This ernbodiment is different from that shown in FIG. I in that the knife and anvil cylinders 54 and 62 respectively, are mounted square with the machine frame in both the horizontal and vertical planes and are not angled. The blanks are fed from left to right as indicated by the arrow and cylinder 52 positioned upstream of the panel cutter cylinder 54 is tilted in the vertical plane. Cylinder 58 downstream of the panel cutter cylinder 54 is also tilted in the vertical plane to the same degree and in the same direction as cylinder 52. The results achieved are the same as in the first described embodiment.

Referring now to FIG. 8 still another alternative embodiment is illustrated. Cylinders 70, 72, 74, 76 and 78 are journalled for rotation in the side frames of the machine with the longitudinal axes of the cylinder parallel to each other and perpendicular to the line of travel of the blanks. In this embodiment cylinders 72 and 76, which are upstream and downstream respectively of knife mounting cylinder 74 are tilted with respect to a horizontal plane. The degree of tilt is the same for cylinders 72 and 76 but is in opposite directions. Accordingly, the blanks will pass under both cylinders or over both cylinders in contrast to the previous embodiments wherein the tilted cylinders were angled in the same direction and the blank went under one cylinder and over the other cylinder.

FIGS. 9 and I0 illustrate alternative embodiments that are of practical advantage wherein space limitations or other extraneous factors make it inconvenient to place the axes of the several cylinders on a common horizontal centerline. For example, in FIG. 9 the blanks travel around and between cylinders 80, 82, 84, 86 and 88 and anvil 90 in substantially the same manner as in FIG. 8. However, in FIG. 9 only cylinder 80, input cylinder 82 and the knife cylinder84 are on the same horizontal centerline. Output cylinder 86 and cylinder 88 are on successively higher centerlines with respect to the horizontal plane of the knife cylinder axis. This construction is advantageous where it is necessary to provide additional space below the window cutting station, for example to accommodate belts, or the like.

As in the previous embodiments the input cylinder 82 and the output cylinder 86 are tilted through the same angle as the angular offset of the cutting knife in order to effect lateral displacement and redirection of the blank. However, since the centerline X of cylinders 86 and 88 are at an angle b with respect to the horizontal centerline of cylinder 84, then the longitudinal axis of cylinder 86 must also be displaced through the same angle b. Thus, cylinders 84 and 86 are not parallel to each other. This is necessary because the tilt of the output cylinder must be in a direction that is perpendicular to the direction of blank travel.

FIG. illustrates an arrangement similar to FIG. 9 but wherein space is provided directly above the cutting station. Cylinder 100 feeds input cylinder 102 which is followed by knife cylinder 104, output cylinder I06 and cylinder 108. Anvil I10 cooperates with the knife cylinder. Once again, the output cylinder is skewed with respect to the knife cylinder by a compound angle that is equal to the angular displacement of the knife and the tilt of the input cylinder as well as the angle b that a plane .r' through the axis of the output cylinder makes with the horizontal.

Although not specifically illustrated, except schematically in FIG. 5, in each instance well known suction means may be used to transfer the blanks from one cylinder to another. Further the knife is secured to one of the cylinders at an angle to the axis of that cylinder and an anvil is positioned in cooperating relationship to the knife.

It will be apparent from the foregoing that an improved and less costly method for cutting windows in envelope blanks is now available. The difficulties encountered with the prior art methods have been eliminated. It is not necessary to reorient all the operations preceding and following the window cutting operation in accordance with the angularly positioned knife on the knife cylinder and the angularly oriented blank. The blank is maintained in a square position with respect to its line of travel at all times. That is, blanks are delivered to the panel cutting section, travels through and are removed therefrom with the side edges parallel to the side frames of the machine. A lateral displacement of each blank along an angled path takes place in the window cutting section but the blank is not angularly oriented. After cutting the window the blank is returned to the center line of the machine for subsequent operations.

lclaim:

1. The method of shear cutting a length of web-like material moving along a longitudinal path comprising the steps of:

a. displacing the material along a path at an angle to its original path while maintaining the side edges of the material parallel to the original path; and

b. cutting the material with a knife means positioned at an angle to an axis that is transverse the original, longitudinal path of the material.

2. The method in accordance with claim 1 including the step of displacing the material along a path at an angle to its original path after the cutting step while maintaining the side edges of the material parallel to its original path. 

